1. Field of the Invention
The present invention relates to a system for isolating a processing room, or "clean room," from contaminants. More particularly, the invention relates to a clean room system that isolates a processing room from contaminants produced by machinery running the production equipment inside the processing room and that provides access by technical personnel to the machinery without requiring their entrance into the processing room.
2. Description of the Related Art
In conventional clean room systems used, for example, in the pharmaceutical, cosmetic, and electronics industries, production equipment typically is located in the central portion of the processing room. Normally, a conventional clean room system also includes a dedicated ventilation system for filtering and recirculating the atmosphere of the processing room. The ventilation system conventionally includes supply ducts in the ceiling of the processing room and return ducts in the walls near the floor. Normally, HEPA filters having efficiencies greater than 99% in removing particles 0.5 micron or larger are positioned in the ventilation system at the terminal end of the supply ducts. The supply air system supplies HEPA Class 100 or better filtered air to the processing room in a manner that produces laminar flow over the centrally located production equipment to "wash" contaminants from the production equipment, from the personnel operating the production equipment, and from any work pieces used with the production equipment. The laminar air flow normally splits at the centrally located production equipment and is directed around each side of the production equipment.
The personnel operating the production equipment within the processing room take special precautions in removing contaminants from their persons and clothing to avoid bringing the contaminants into the processing room. Conventionally, the processing room is maintained at an atmospheric pressure higher than that of adjacent environments to ensure that any atmospheric leakage is from the processing room rather than into the processing room. It is well known in the art that a clean room can atmospherically isolate a processing room without requiring the processing room to be hermetically sealed from adjacent environments. As long as the atmospheric pressure in the processing room is sufficiently higher than that of adjacent environments, and the cumulative cross-sectional areas of passageways providing atmospheric communication between the processing room and the adjacent environments is sufficiently small, contaminants from adjacent environments will not enter the processing room. Government regulations governing clean room systems used in the pharmaceutical industry, for example, require the processing rooms to be maintained at an atmospheric pressure at least 0.5 inch column of water higher than that of adjacent environments.
Because of the necessity of keeping contaminants from the processing room, clean room systems are particularly costly to construct, maintain, and repair. When technical personnel must have access to the processing room to repair or maintain the production equipment, they must go through the same cleansing procedures followed by the production personnel before entering the processing room. The cleansing procedures apply not only to the technical personnel and their clothes, but also to the tools, replacement parts, and other equipment they must bring into the processing room. Consequently, if a maintenance or repair person discovers, after entering the processing room, that he lacks the proper tool to make the repair, he must leave the processing room and start the cleansing process anew before reentering with the proper tool. Furthermore, because the machinery actuating the processing equipment inside the clean room often must be exposed to accomplish repairs and maintenance, contaminants such as oil, dust, and other particles from the machinery also will be released into the clean room atmosphere by the technical personnel. To limit the contamination from the actuating machinery, the processing line normally must be shut down, the production personnel must leave the clean room to avoid picking up such contaminants, and all work pieces must be removed from the vicinity of the exposed machinery. All of these precautions cause delays and increase the cost of operating a clean room system and, subsequently, the cost of the goods being manufactured or processed.
Similar problems exist in industries that process hazardous materials such as munitions, atomic fuel, toxic chemicals, and atomic waste. Hazardous material processing systems conventionally isolate the production personnel from the production equipment by the use of special suits that are in atmospheric communication with an adjacent room but are isolated from the processing room containing the hazardous material production equipment. When the production equipment must be repaired or maintained, the processing room must be cleared of all hazardous material to enable the technical personnel to enter the room and work on the production equipment.
The present invention is intended to provide an improved clean room system that provides technical personnel with access to the machinery actuating the production equipment inside a clean processing room without requiring them to enter the processing room itself.
The present invention also is intended to provide a clean room system that isolates a clean processing room from contaminants emitted by the machinery operating the production equipment inside the processing room while the production machinery is being operated as well as during maintenance.
Furthermore, the present invention is intended to provide a system for isolating the atmosphere of a hazardous material processing room from machinery that actuates the production equipment in the processing room and provides access by technical personnel to the machinery without requiring them to enter the hazardous processing room.
Additional advantages of the present invention will be set forth in part in the description that follows and in part will be obvious from that description or can be learned by practice of the invention. The advantages of the invention can be realized and obtained by the system particularly pointed out in the appended claims.